Automatic telephone-system selector.



P. R. "MU'BBRTY. AUTOMATIC TELEPHONE SYSTEM SELEGTOR. APPLICATION FILED FEB. 10, 1910.

Patented May 26, 1914.

VV/inesses: //7 yen/0r P. R. MQBERTY. AUTOMATIC TELEPHONE SYSTEM SELECTOR.

APPLICATION FILED FEB. 10, 1910. 1,697,927. Patented May 26, 1914,

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P. R. MoBERTY.

AUTOMATIG TELEPHONE SYSTEM SELBG'IVOR.

APPLIUATION TILED FEB. 10, 1910 PatentedMay 26, 1914.

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ITED STATES PATENT OFFICE.

FRANK R. MCBERTY, OF NEW ROCHELLE, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, OF NEW YORK, N. Yl, A CORPORATION OF ILLINOIS.

AUTOMATIC TELEPHONE-SYSTEM SELECTOR.

Specification of LettersPatent.

Patented May 26, 1914.

Application filed February 10, 1910. Serial No. 543,087.

certain new and useful Improvement in- Automatic Telephone- System Selectors, of

which the following is in full, clear, concise, and exact description.

My invention relates to automatic telephone selectors of that type wherein brushes connected either directly or through suitable mechanism to telephone lines are adapted to traverse stationary terminals connected with trunks or lines.

The object of my invention is to provide in such a switch a grouping and mounting of the parts which will insure the terminals being supported in a rigid relation with respect to the brushes, will simplify the wiring and will generally improve the operation and appearance of the selector.

Heretofore in selector switches of this type the terminals which are usuallystamped from sheet metal have been mounted one above the other with strips of insulating material interposed between the adjacent ones and the entire group secured together by means of suitable clamps. The mounting of the. terminals in this manner is a tedious operation, is very unstable due to the tendency of the terminals to slip from between the insulating layers, and is generally unsatisfactory.

According to this invention, 1 mount a number of terminals in one group, each group comprising a unit, and the units for each switch being adapted to be assembled in a common mounting. Each of said units comprises a block of insulating material, preferably hard rubber, in which are socured a number of suitable terminals arranged in a single. straight row, and preferablymolded into said insulating block. Each block is adapted to, be mounted iii a frame with the row of terminals therein at right angles to-the plane of movement of the movable brushes; each of said blocks being proidod with suitable fastening devices adaptcd to retain said blocks in a. frame.

My invention may be better understood by reference to the accompanying drawings in which it is shown in the form it will take when applied to a selector wherein the brushes are mounted to rotate about a vertical axis,'and the terminals are mounted concentrically with respect to the said axis.

In said drawings, F igurel is a view infront elevation ofa terminal frame with a number of the blocks removed; Fig. 2 is a plan view of the same; Fig. 3 is a vertical sectional View taken upon line 3-3 of Fig. 1; Fig. 4. is a view in side'elevation of one of the insulating blocks with a part in section; Fig. 5 is a view in front elevation of one of said blocks with a part in section; Fig. 6 is a perspective view of one form of terminal which may be used; Figs. 7 .and 8 are perspective views of modified forms of terminals;and Fig. 9 is a perspective view of a securing device used in connection with the insulating blocks.

Like reference characters designate like parts throughout the drawings.

As shown in Figs. 1, 2 and 3 of the drawings, 5 and 6 designate upper and lower frame bars which in the particular form of selectors, are of curved segmental form and are adapted to be secured at their ends to auxiliary frame members 9 and 10, which members are adapted to be secured to the main frame members of the selector. Each of said frame bars is provided in its opposite margins with a plurality of radially arranged notches l5, 15 which are adapted to receive fastening devices carried by termi nal blocks l6, 16 as will hereinafter appear.

A brace rod 17 adapted to stifi'errthe segmental frame bars is mounted between said frame bars atthe central portion thereof and secured thereto by suitable means such as machine screws 18, 18. Referring now to the particular form of terminal block which i has been found adaptable for use in connection with a selector of this type, the same comprises a block of insulating material, such as hard rubber, which is generally rectangular in shape with all of its sides parallel. Said blocks are adapted to be supportcd between the frame members 5 and 6 and for this purpose are provided at their ices supports the terminal blocks in a rigid vertical position with the inner margins thereof meeting while the outer margins thereof are spread or fanned slightly to permit the easy attachment of the wires to the outer ends of terminals 30, in said blocks, said terminals being adapted at their inner ends to be traversed by movable brushes as shown in Fig. 2. .As'shown each of said blocks, contains a single row of terminals, the

ends of which project through the edges of said blocks, the ends to make contact with the brushes projecting only a slight distance beyond the body of said block, while the ends to which the wires are to be attached project a greater distance beyond the block on the edge thereof opposite to the edge through which project the ends to make contact with the brushes.

The terminals 30 may be of any suitable form which will permit the eas attachment of the wires and will afford su cient contact for the movable brushes. One form of terminal which I' have found to be well suited for this purpose and shown in Fig. 6 is generally rectangular in cross-sectional shape and is provided at one end with a notch afiording a seat for connection with a wire and is slightly rounded on its opposite end to permit the brushes to be moved thereover. As hereinbefore stated, said terminals are mounted n straight rows in the terminal blocks 20 preferably by molding said blocks around the terminals. In order to prevent the terminals being pressed outwardly by contact of the movable brushes thereon, or turning in their mounting blocks, it is found desirable to provide upon each of said terminals along the portion thereof which is inclosed in said block an irregular or rough ened surface. The particular form of irregularities with which each of these terminals is provided is of little consequence so long as it permits the rubber, or other insulating material, to grip the terminals with sufiicicnt force to prevent its turning or other movement within said block and does notunduly weaken the terminal. One form of such irregularity, which has been found suitable, is that shown in Figs. 5 and 6 and comprises a plurality of indentations 40, i0 arranged in longitudinal relation in' one surface of said terminal. This irregular portion of the terminal, however, may be formed as shown in Fig. 7, in which said terminal is illustrated as being twisted through an angle of 90 degrees, or may be as shown in Fig. 8, in which two of the faces of said terminal are roughened by transversely arranged notches 42, 42.

In mounting the terminal blocks made in accordance with this invention one of the curved frame members, preferably the up per one is removed from the base member and the blocks are mounted with one end thereof resting upon the lower frame members and the legs of the U-shaped securing strips in that end of said block engaging the notches in said lower frame member, the other frame member is-then brought into position across the upper ends of the terminal blocks with the notches therein in position to engage the fastening devices in the said upper ends of said blocks. The said frame members may be secured to the base members by machine screws or other suitable forms of clamping devices.

The advantages of a terminal mounting tion are numerous, it being obvious that such amounting provides a grouping and mounting for the terminals whereby same may be easily assembled and wired, and also tends to the best operation of a selector in connection with which it is used. Moreover, the provision of the fastenin devices in the ends of the terminal blocks which engage the notched frame bars not only affords a rigid support for said blocks which prevents their being skewed or otherwise displaced in the movement of the brushes over the terminals but also avoids the use of screws or other similar fastening devices which would tend to weaken said blocks. The further advantage of forming the terminal blocks by molding the same around the terminals and securing clips is perfectly obvious inasmuch as it not only securely retains said terminals and clips in place, but blocks of the correct size and shape can thus be easily formed without the necessity of the expensive machining operations.

Having described my invention, I claim l. A selector switch having stationary terminals adapted to be traversed by movable brushes, and insulating blocks in which said terminals are mounted in straight rows, said insulating blocks being mounted with the rows of terminals therein transverse to the direction of movement of said brushes.

2. In a selector switch in combination a plurality of terminals adapted to be traveach supporting a straight row of said terminals, and means for rigidly supporting said blocks with the straight rows of terminals at right angles to the direction of movement of said brushes.

3. In a selector switch in combination, a plurality of terminals adapted to be traversed by movable brushes, insulatingblocks each supporting a straight row of said terminals, and a frame adapted to rigidly support said blocks with the straight rows of terminals at right angles to the direction of movement of said brushes.

4. In a selector, a plurality of rows of fixed terminals, insulating blocks each supporting a single row of said terminals, fastening devices embedded in the ends of sald constructed in accordance with my invenersed by movable brushes, insulating blocks insulating blocksand projecting therefrom, and frame members provided with notches to receive said fastening devices. 7

5. In a selector switch, a terminal mounting block, U-shaped fastening devices embedded in said'blocks with the legs thereof projecting through the end margins of said blocks, on their opposite margins with notches adapted to receive the legs of said fastening devices.

6. In a selector switch in combination a frame embracing upper and lower curved supporting plates, fiat terminal blocks se- 15 cured at their ends to said supporting plates and frame members each provided.

and arranged in an edgewise radial relation to the center of curvature of said plates, and one row of terminals carried by each block, the inner ends of said terminals forming contact surfaces for movable brushes and the outer ends thereof being adapted for attachment of connectin Wires. o

- In Witness whereof, hereunto subscribe my name this 9th day of February 1)., 1910.

IRVING MACDONALD, 1 HORACE S. KING. 

